02RedHawk

iTrader: (17)

Curious.....No, concerned....

I'd like to purchase a set of LS6 (243) ported heads (PRC or PP), but I am concerned about the loss of low-end torque when installing the heads onto my TB-SS with the STOCK (~'01 LS6) camshaft.

Since the TB-SS is hefty (4600#), low-end grunt is pretty critical to get the hulk up and movin'. I am retaining the stock cam for warranty & reliability purposes, but am considering a set of "mildly" ported 243 heads w/ stock int/exh valves & springs to get a bit more uummpph from the motor (but keeping it looking 100% stock, even if the valve-covers are removed). Obviously, TSP-PRC and PP both have low-budget (that's ME!) 243 heads that have very good flow from .200-.500" lifts, which is all I would need.

BUT, the PRCs have supposedly ~235-237cc intake runners, and the PPs have runner volumes of approx 227cc's. Stock 243 runner volume is about 212cc's. So, will this extra runner volume really make a noticable loss in low-end power when coupled with the stock cam? Any guess as to how much? Bear in mind that I'd be using them on a truck that is roughly 1000-lbs heavier than an F-Body, so a "slight" loss of low-end torque as-felt in an FBody would only be amplified if/when installed on a TB-SS.

I want to pull the trigger on this, BUT I am not willing at all to sacrafice low-end grunt if I do this.

Thoughts / opinions / help?

Brainful

need to know 2 .. am not SURE .. but u can cure this loss by adding extra compression .. i said not sure

slimcracka

iTrader: (7)

yes i was wondering the same thing any one chime in lol

slowpoke96z28

iTrader: (2)

if you are worried about your warranty, don't do it. there is a reason the casting numbers are on cylinder heads, and that's the first thing the dealership is going to look at.

02RedHawk

iTrader: (17)

Thanks for the concern, I'm well aware of that. Hence, the need for 243 castings. Nevertheless, this isn't the topic of my thread.

cantdrv65

iTrader: (3)

If you look at dyno graphs of either PRC or PP Ls6 heads...its obvious the gains are across the board. It gains torque even at the lower RPMs so I wouldnt be worried about it. I slapping my PRC Ls6 ers on now.....

67Ranger

iTrader: (16)

i dont know if they do this on the LS6 heads, but my patriot heads say "PATRIOT" real big across the front of them, and the dealer would probably notice.

cantdrv65

iTrader: (3)

Hmmmm, the TSP PRC heads just have the stock 243 casting numbers.

02RedHawk

iTrader: (17)

...and that wouldn't be on there if you ask to not have them engraved....!

02RedHawk

iTrader: (17)

Yea, I saw that. But those dyno graphs are with rather big cams, so I worry about how they'll (the heads) behave with the stock cam in there... (??)

Still, that data is somewhat reassuring!

slowpoke96z28

iTrader: (2)

if you have the heads milled to increase the compression ratio, you should be ok. use stock type bolts, gaskets, and if the bolts are marked with paint, be sure to mark the new bolts the same way.

orangeapeel

iTrader: (18)

If you have a mill for higher CR then that should help out.

Steel Chicken

iTrader: (3)

if you lose low end torque with stock cam and a head upgrade, you picked the wrong heads. pick a head that doesnot have huge monster ports. the good ones properly selected for your application will GAIN you uber torque.

camarokid94

iTrader: (2)

LOL just slap some AFRs on the stock stuff like im doing till my 408s done.
steel is right you shouldnt loose anything on the bottom unless there like a 245cc intake runner. you said you want a mild ported head. this should help across tghe board and really shouldnt hurt. just remember to not go to big!!! best idea is to call patriot or who ever you want to get the heads from. TSP is also a good choice (jason) and tell them what you want to do and they can get you the head that you will need. they will know better than the guys on here , myself included, that are making a good guess at what will happen.